In this paper, a thermomechanical modelling of the material flow is developed, and the tool–chip contact length and the sliding–sticking zones are characterised analytically. Furthermore, the finite element method is used to solve the non-linear thermal problem in the chip. The effect of cutting conditions and material behaviour on the sliding–sticking zones and on the temperature distribution and local friction along the tool–chip interface is evaluated. It has been found that the sliding–sticking zones strongly control the local conditions of stress, velocity and temperature. A qualitative comparison between the proposed model and experimental results is provided.